dt-bindings: backlight: Add some common backlight properties

Let's use a common.yaml include for the backlight like we do with
the LEDs. The LEDs are inherently incompatible so their bindings
cannot be reused for backlight.

Cc: [email protected]
Suggested-by: Sam Ravnborg <[email protected]>
Signed-off-by: Linus Walleij <[email protected]>
Reviewed-by: Daniel Thompson <[email protected]>
Reviewed-by: Rob Herring <[email protected]>
Signed-off-by: Lee Jones <[email protected]>
1 file changed